Move FileEnumerator to its own file, do some refactoring.

chrome/browser/chromeos/drive/file_cache_metadata.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/drive/file_cache_metadata.h"
 
 #include "base/callback.h"
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/metrics/histogram.h"
 #include "base/sequenced_task_runner.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
 #include "chrome/browser/chromeos/drive/file_cache.h"
 #include "chrome/browser/chromeos/drive/file_system_util.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
 
 namespace drive {
 namespace internal {
 
@@ skipping 44 matching lines @@
 // The resource IDs and file paths of discovered files are collected as a
 // ResourceIdToFilePathMap, if these are processed properly.
 void ScanCacheDirectory(
     const std::vector<base::FilePath>& cache_paths,
     FileCache::CacheSubDirectoryType sub_dir_type,
     FileCacheMetadata::CacheMap* cache_map,
     ResourceIdToFilePathMap* processed_file_map) {
   DCHECK(cache_map);
   DCHECK(processed_file_map);
 
-  file_util::FileEnumerator enumerator(
+  base::FileEnumerator enumerator(
       cache_paths[sub_dir_type],
       false,  // not recursive
-      file_util::FileEnumerator::FILES |
-      file_util::FileEnumerator::SHOW_SYM_LINKS,
+      base::FileEnumerator::FILES | base::FileEnumerator::SHOW_SYM_LINKS,
       util::kWildCard);
   for (base::FilePath current = enumerator.Next(); !current.empty();
        current = enumerator.Next()) {
     // Extract resource_id and md5 from filename.
     std::string resource_id;
     std::string md5;
     std::string extra_extension;
     util::ParseCacheFilePath(current, &resource_id, &md5, &extra_extension);
 
     // Determine cache state.
@@ skipping 481 matching lines @@
       new FakeCacheMetadata(blocking_task_runner));
 }
 
 void FileCacheMetadata::AssertOnSequencedWorkerPool() {
   DCHECK(!blocking_task_runner_ ||
          blocking_task_runner_->RunsTasksOnCurrentThread());
 }
 
 }  // namespace internal
 }  // namespace drive